Abstract: The invention relates to a method for analyzing the diversity of the catalogue of T and/or B lymphocytes in an individual, based on the amplification, from a sample, of genomic DNA fragments by PCR multi-n-plexes, with n?2, carried out with a combination of at least 3 primers defining at least 2 primer couples, each of which includes a primer specifically hybridizing upstream and/or in a given V or D gene and a primer specifically hybridizing downstream and/or in a given J gene, in order to obtain the amplification of at least two fragments characteristic of two distinct V-J or D-J rearrangements from each primer couple. The invention also relates to the applications of this method, in particular in the treatment follow-up or in the diagnosis and/or prognosis of certain diseases.